The invention relates to a shutoff or control.
In valves where forces act on the spindle transverse to the spindle axis, the spindle must be supported in the housing. The danger of unacceptably large transverse forces arises primarily in valves where the displacement during actuation is large. Gate valves, in particular, are to be mentioned here. Support is achieved by means of ribs or grooves on or in the housing, or by means of special abutments which surround the spindle and are in contact with the housing wall.
FIG. 3 of the German patent 1 959 547 shows a valve which is equipped with an abutment of sheet metal. The abutment has an outwardly directed flange which surrounds the spindle, and the spindle can slide up-and-down in the outwardly directed flange. The abutment is provided with a circumferentially extending collar which bears against the housing wall where it is secured in a manner not indicated in detail.
To the extent that they are arranged near the valve seat, supports or abutments which are fixed relative to the housing allow only a relatively short stroke of the spindle. Accordingly, they cannot be used for gate valves and valves with a stroke of similar length. On the other hand, if the support is disposed at a location farther away from the valve seat in such a manner as to permit the full opening stroke of the closure or control element, its supporting function is necessarily limited. Due to the large spacing from the support, the transverse forces which are generated by the flow and act on the closure or control element can, in an extreme case, lead to such great deflection of the closure or control element that its function is no longer assured.